A couple of years ago, a memo from David Mamet, the creator of The Unit, to the show's writers emerged online, in which he outlined, in no uncertain terms, how to make the drama hang together: "Any time two characters are talking about a third, the scene is a crock of shit … any time any character is saying to another 'as you know', that is, telling another character what you the writer need the audience to know, the scene is a crock of shit … do not write a crock of shit."

OK, so The Unit is rightwing, jingoistic, militaristic and even rather xenophobic. But it's certainly not a crock of shit. The series, which first aired on CBS in 2006 and ran for four seasons, is based on Eric Haney's military memoir Inside Delta Force; it follows the lives, both professional and personal, of a tight-knit group of elite US operatives – or "covert warriors, unsung heroes" as the box set cover has it. The first season sees our heroes deployed everywhere from Afghanistan to Indonesia, grappling with a jet hijacking, carrying out covert assassinations, recovering a crashed satellite and generally doing Uncle Sam's dirty work. At the same time, they have to keep their relationships with their women back home on some sort of even keel.

The whole thing could be used as ammunition for those who feel that Mamet, the writer of Glengarry Glen Ross, has taken a bizarre, ideological wrong turn in his career. But that's for another article. Despite its arguable flaws, it's gripping drama. At the heart of the show is the team's leader, Jonas Blane, played by the supremely charismatic Dennis Haysbert (why isn't he a bigger star?). But Regina Taylor as his wife Molly, matriarch to the wives and girlfriends, is an equally important character. And they're the key to the drama's success.

Although the action scenes are taut, exciting and well staged, the various women are given time and space to develop their own plotlines and characters, as well; the result is a fantastic group dynamic with each wondering if this is the mission their husband won't come back from, while trying to juggle work and family. The mixture of military action and domestic drama gives the show its unique twist, as we cut between the guys taking out some desert-dwelling warlord and a wife back home having an affair.

Unexpectedly, the parallel dramas manage to be equally gripping. These are flawed people: middle-aged Blane knows he's nearing the end of his life on the front line but, despite Molly's pleas, can't stomach walking away. Meanwhile, his deputy Mack has a troubled – and even violent – relationship with his wife, as he struggles to separate his job and his home life. It can be uncomfortable to watch.

For me, though, episode six in the first season, called Security and penned and directed by Mamet himself, provides the show's standout moment, a sublime mini-masterclass in character and plotting. The team, in Beirut, has to plant a bug near the Iranian ambassador in order to eavesdrop on a conversation between him and his Russian counterpart. Even as the characters openly discuss the art of misdirection and sleight of hand, we ourselves are being led down the garden path by Mamet. I don't want to give away any more than that, other than to say it's a perfect piece of storytelling.